Cut-off valve



3 Sheets-Sheet 1.

(No Mode'L).

' B. BRAZELLE.

yGUT-OFF VALVE. Y

Patented Mar; 21,1882.

(No Model.) s sheets-sheen 2."

B. BRAZEL-LB.

GUT-01T VALVE.

No. 255,136. PatentedMar. 21.1882.

N. PETERS. Phom-Lnhngmphu. wnshingwn. 11C.

(No Model.) 3 sheets-'sheet 3.

B. B MZELLE.v

y CUT-OPF VALVI?l No. 255,136 y Patented Mar. 21,1882l was.

WITNESSESZ I vVEN-TOR WQ; Mm@ d@ dUNITED STATES PATENT OFFICE.

BENJAMIN BARAZELLE, OF ST. LOUIS, MISSOURI.

CUT-OFF VALVE.v

SPECIFICATION forming part of Letters Patent No. 255,136, dated March21, 1882.

Application filed December 1, 1881. (No model.)

To ali whom it may concern Beit known that I, BENJAMIN BEAZELLE, of St.Louis, in the county of St. Louis and `State of Missouri, have inventedcertain new and useful Improvements in Cut-'Off Valves, ot' whichimprovements the following is a specification.

The object of my invention is to simplify and perfect the constructionand operation of mechanism for cutting off steam, either automaticallythrough the action of -a governor' or at determined points in the strokeof the enginepiston; and to this end my improvements consist in certainnovel devices and combinations embracing an open-ended cylinder, dividedcentrally by a partition and located within the steam-chest of theengine, said cylinder having specially-arranged steam andexhaustpassages adapted to communicate at proper intervals with thesteam-chest and main exhaustports, a pairv ot' pistons working in saidcylinder and serving to eect the opening and closing of steam-ports inthe main distributionvalve, a slide-valve governing the admission ot'steam to and exhaust from the cut-od' cylinder, and a controlling valve,the position of which is regulated either by hand or by the governor,and which serves to regulate the period o f admission of steam to thecut-off cylinder. y

The improvements claimed are hereinafter more fully setforth.

.In the accompanying drawings, Figure 1 is a vertical longitudinalcentral section through the steam-chest and -portion of the cylinder ofa steam-engine embodying my invention; Fig. 2, a plan or top View of thevalve and cut-olil cylinder; Fig. 3, a vertical transverse section atthe center of the cut-off cylinder and main exhaust-passage; Fig. 4, anend view', and Fig. 5 a transverse section at the center of one of itsexhaust-ports of the cut-oft' cylinder; Fig. 6, a vertical longitudinalsection through a steam-'chest and portion of a steamengine cylinder,showing a moditication of my invention; Fig. 7, a plan or top view ofthe valves and cut-oft' cylinder ofthe same, Fig. 8, a verticaltransverse section of the same at the center of the main exhaust-port,and Figs.

9 and 10 vertical longitudinal and vertical transverse sections,respectively, through the steam-chest and portion of the cylinder of asteam-engine, showing a further modification rof my invention.

My improvements are herein described and shown as applied in asteam-engine having a cylinder, 1, piston 2, steam-chest 3. inductionand eduction passages 4 5, and exhaust passage 6, all of the ordinaryconstruction. The main distribution-valve 7 is a double-ported slide,operated by a stem, 8, and composed ot two end sections, (each having asteam-port, 9, and exhaust-cavity 10,) united by tvvo longitudinal barsor bridges, 11. Theindependent.

cut-off valve, which consists of two plates, 12,

connected by longitudinal bars 13,rides upon the back of the main valve7, and performs the function of cutting off steam at desired points bycorrespondingly closing the steamports 9 ot' the main valve, the cut-offvalve being reciproeated for this purpose by pistons Working in anindependent cut-oil cylinder. Such reciprocation may be effected eitherautomatically, as determined by the governor, or

in conformity with a iiXcd grade ot expansion, and arrangements of theparts suited to either case are shown in the drawings, and will behereinafter described.

Referring to Figs. 1 to 5, inclusive, iu which my improvements are shownas .adapted to4 automatic cut-off, with range of expansion from zero toa Vlate period of the stroke, the cut-off valve 12 `is operated by twopistons,

14, each formed with. or connected to a rod,

15, and fitting, in line one with the other, on opposite sides of acentral partition or division, 16, in an open-ended cut-off cylinder,17, secured within the steam-chest 3 midway between the faces over whichthe main valve 7k works. Each of the piston-rods 15 has apair ofcollars, 18, at and adjacent to its outerend,

between which collars is fitted a cross-bar, 19,

connecting the longitudinal bridges 13 of the cut-off valve 12, therebycoupling the pistons and valve together, and thus securing theirsimultaneous longitudinal movements. The pistons 14,` being exposed toequal pressure on their outer faces, are perfectly balanced, and

will consequently be moved together in one or the other direction uponthe admission of steam behind either of them, respectively.

An exhaust-passage, 20, is formed in the central partition, 16, of thecut-off cylinder 17, establishing communication between the space abovethe upper side thereof and the main exhaust-passage 6 of the cylinder 1,and exhaustports 21 are formed in the cut-oft' cylinder on each side ofthe partition 16, and at a sufficient distance therefrom to providespace for the cushioning of the pistons 14 when at the inner` extremityof their stroke, the ports 21 affording exit for the steam on the innersides of the pistons and admitting of the escape thereof through thecentral passage, 20. The cut-off cylinder 17 is flattened and widenedupon its top for the major portion of its length, forming a face overwhich works a slide-valve, 23, connected to a stem, 24, and reciprocatedthereby from a suitable eccentric or rock-shaft. rlhe exhaust-recess ofthe valve .13 serves to establish communication between the centralexhaust-passage, 20, and one or the other alternately of theexhaust-ports 21, and steam is admitted alternately behind one or theother of the pistons 11 through elongated ports 25, located in theslide-valve 23 adjacent to its sides, and extending in oppositedirections on each side of its transverse center line. r1`he ports 25 inthe traverse of the valve 23 cover and uncover steam-supply passages 26,the upper ends of which are located in line trailsversely upon the topof the cut-off cylinder 17, and which extend in opposite directions andterminate within the cylinder 17, one on each side of the centralpartition, 16.

It will be obvious that according as the steam-passages 26 are openedearlier or later in the stroke by the valve 23, so will the degree ofexpansion effected by the closing of the supply-ports ofthe maindistribution-valve through the movement of the pistons 14 and cut-ott'valve 12 be greater or less, as the ease may be. Such variation iseffected by a controlling-valve, 27, which is secured upon a shaft, 28,fitted so as to be capable of axial movement in a bearing in thesteam-chest cover, coneentrically with the central exhaustpassage of theeut-off cylinder. AThe controlling-valve 27 is formed of a central hubor boss and two laterally-projecting arms, the lower surfaces of whichare faced truly and it over the correspondingly-faced upper surface ofthe slide-valve 23. The position ofthe valve 27 is shifted, as requiredfor different points of cut-oit', by means of an arm, 29, on the outerend of the shaft 2S; and by connecting the arm 29 with the governor ofthe engine the speed of the engine is regulated by the automatic cut-offthereby effected. The valve 27 may be shifted by hand where automaticcut oli' is not deemed necessary.

It will be seen that according as the arms of the controlling-valve 27are moved nearer to the transverse center line of the eut-olil cylinderin the direction of the arrows, Fig. 2, so will the period during whichsteam is admitted to the lnain cylinder l be lengthened, as steam willin such case be admitted later to the cut-olf cylinder 17 through theslidevalve 23. Conversely, the farther the arms of the controlling-valveare moved from the transverse center line thc earlier will the cut-ott'valve be moved and the point of cut-olf effected. r1`he ports 25 in theslide valve 23 are elongated for the purpose of keeping the valve incommunication with the cylinder-port when the controlling-valve 27 isadvanced for the later grades of cut-oli", and the exhaust-recess in thevalve 23 is correspondingly elongated.

Two sets of portsto wit, one steam and one exhaust-for each end of thecut-oit' cylinder are essential, for the reason that when the piston hasclosed the exhaust-port to providey for cushion steam cannot enter bysaid port anda separate steam-port must be provided in line with orclose to the central partition. By the location of the exhaust-ports insuch relation to the central partition as to provide space between theirinner sides and the faces of said partition a simple and inexpensivecushion is provided, preventing jar or shock at the ends of the strokeof the pistons and dispensing with the air cylinders, dash-pots, andsimilar appliances ordinarily used. The employment of the open-endedcut-oli` c\lin der enables stuffing-boxes to be dispensed with, with thebeneficial result of avoiding the friction thereof, thenecessityofcorrect alignment, and the inconvenience of maintainingstufiingboxes located in a steam-chest where ready and convenient accessto them would be impracticable.

The modilicationofmy improvements shown in Figs. 6 to S, inclusive, isdesigned more particularly for engines of small power, where economy inconstruction is an object. ln this case the range of variation of thepoint of cutoff is more limited than in the instance first described,not extending farther than to about one-third of the stroke of the mainpiston. The cut-off cylinder 17 is here made part of and travels withthe main distribution-valvc 7, and the slide-valve 23 is dispensed with,the controlling-valve 27 fitting directly over the flattened uppersurface of the cut-off cylinder and effecting the opening and closure ofthe steam supply passages, 26, (which as in the previous instance, leadinto the cut-oli' cylinder on opposite sides of its central partition)by the traverse of the cut-oil' cylinder beneath it. The centralexhaust-passage ot' the cut-011l cylinder is likewise dispensed with,the exhaust-passages 21 extending through the main valve and terminatingon its lower working-face, where they com municate at the properintervals, regulated by the movements of the main valve 7, with channels30, formed in the cylinder-valve face and leading into theeduction-passage 5. The independent cut-off valve 12 is connected to andreciprocated bythe pistous 14E of the cut-off cylinder in the mannerhereiubefore described.

A further modification of my improvements, adapted for a eut-off fixedat about one-third the stroke, and likewise designed particularly with aview to effect economy in cost of construction, is shown Figs. 9 and 10.The cut-oft'eylinder 17 is, as last above described, cast in a piece andtravels withthe main valve 7. The steamports 9 of the main valve areclosed to eifect the cut oil", and opened thereafter for the succeedingadmission of steam by pistons 3l, secured upon a rod, 32, which passesthrough the long` central partition, 16, of the eut-off cylinder. Theexhaust-passages 21 of the cutot'f cylinder are, as before, located oneach side 0f the central partition and communicate With channels 30 inthe cylinder valve-face, leading to the eduction-passage 5. i The.steampassages 26 of the cut-oft cylinder lead from the spaces at eachend ot' the partition 16 to the working-face ofthe main valve, and areuncovered at the proper intervals to admit steam to each of thelpistons, respectively, by the movement of the main valve over itsWorkingfaces upon the cylinder. The construction shown is adapted onlyfor a tixed cut-off, and a throttling-governor is required forregulation; but automatic regulation may, if desired, be provided bycausing the steam-supply passages 26 to open upon the top ot' thecut-off cylinder, and using in connectiontherewith acontrolling-valve,27,ashereinbetbredescribed.

I am aware that an auxiliary cylinder and piston combined with andyemployed to operate the main or the eutloff valve of a steamengine havebeen lieretoforeknown and used, as exemplied in the patents of W.Shepherd, Jr., No. 23,885, May 3, 1859, and Babcock and Willcox, No.54,090, April 24, 1866, and such therefore I do not broadly claim.

I claim as myinvention and desired by Letters Patent- 1. Thecombination, substantially as set forth, of an open-ended cylinderhaving a central division or partition and a steam and an exhaust porton each side thereof, a pair of pistons fitted yto said cylinder onopposite sides to secure of its central partition, and a stationarycontrolling-valve whichiits over the steam-ports of the cylinder and isadjustable, so as to regulate the period of admission of steam thereto.

2. The combination, substantially as set forth, of'an open-endedcylinder having a central division or partition and a steam and anexhaust port on each side thereof, a pair of pistous, each tted to saidcylinder on one side of said partition, a slide-valve effecting theopening and closing ofthe steam and exhaust ports, and au adjustablecontrolling-valve regulating the period of admission of steam throughsaid slide-valve.

3. The combination, substantially as setforth, of a double-ported slidedistribution-valve, an openended cylinder connected to said valve andhaving a central division or partition, a pair of steantsupply portsleading into said cylinder onv opposite sides of said partition, a pairof exhaust-ports extending from said cylinder through 'the distributionvalve to its Working-face on opposite' sides of said partition, andavalve-face upon the main steamcylinder having channels or groovesleading to its eductiou-passages, with which channels the exhaust-portsin the distribution valve leading to the open-ended cylinder are adaptedto be. alternately brought into communication by the reciprocation ot'the valve.

4. The combination,substantially as set forth, of a double-ported slidedistribution-valve, au open-ended cylinder having a central division orpartition and a steam and an exhaust port on each side thereof, a pairof pistons fitted to said cylinder on opposite sides of the centralpartition, a cutoff valve connected to the rods ot' said pistons andgoverning the ports of the distribution-valve, a slide-valve governingthe ports ot' the open-ended cylinder, and an adjustablecontrolling-valve regulating the admission of steam through saidslide-valvel to said ports.

BENJAMIN BRAZELLE.

Witnesses:

CORNELIUS V. OHAPIN, ELIAS F. GILBERT.

